There exist many variations of electrochemical sensors which, although they may appear similar, function vastly differently. For example, some electrochemical sensors can be used for detection of the presence of a specific gas while others detect concentrations of a specific gas. Even further some electrochemical sensors function with liquids and do not function with gases. Focusing on electrochemical gas sensors, some of these gas sensors use galvanic reactions while others use catalytic reactions. Further, some of these gas sensors need electricity to function while others do not need electricity and in some instances these sensors actually generate electricity. Even further, within similar types of electrochemical gas sensors that have the same electrical requirements, this small subset of sensors can have a vast amount of variation depending on the function of the cell and/or the gas which the cell reacts with.
Focusing on catalytic type electrochemical gas sensors, these sensors are typically used as toxic gas sensors. When used as toxic gas sensors (e.g., for monitoring of smoke stacks emissions) these sensors may only be exposed to the toxic gas for short durations of time or intermittent duty times and/or they may only be used to detect significantly low concentrations of a gas (e.g., gas in the parts per billion (PPB) range). However, unlike the way these sensors are used as toxic gas sensors, systems for delivering therapeutic nitric oxide gas to a patient can use catalytic type electrochemical gas sensors to confirm accurate dosing of therapeutic gas such as inhaled nitric oxide (NO). These delivery systems, that include catalytic type electrochemical gas sensors, can be used to deliver therapeutic nitric oxide to a patient at a dosage in the parts per million (e.g., 1 PPM to 80 PPM, 0.1 PPM to 80 PPM, etc.) for a prolonged period of time (e.g., many hours, days, weeks, months, etc.) under continuous gas monitoring.
Generally speaking, this type of use of catalytic type electrochemical gas sensors in systems for delivering therapeutic nitric oxide gas to a patient is considered to be atypical and may present problems not seen when using these sensors in a more conventional manner (e.g., typical toxic gas sensor applications). These issues, can be important as users (e.g., doctors, nurses, etc.) may confirm dosing of the therapeutic drug based on the output of these sensors. Accordingly, a need exists to overcome these issues for at least ensuring proper confirmation of dosing.